Exam 22: Magnetic Forces and Magnetic Fields

Each of two parallel wires separated by 6.0 mm carries a 40-A current.These two currents are in the same direction.Determine the magnitude of the magnetic field at a point that is 5.0 mm from each of the wires.

Two long parallel wires separated by 4.0 mm each carry a current of 24 A.These two currents are in the same direction.What is the magnitude of the magnetic field at a point that is between the two wires and 1.0 mm from one of the two wires?

A charged particle (mass = 4.0 $\mu$ g,charge = 5.0 $\degree$ C)moves in a region where the only force on it is magnetic.What is the magnitude of the acceleration of the particle at a point where the speed of the particle is 5.0 km/s,the magnitude of the magnetic field is 8.0 mT,and the angle between the direction of the magnetic field and the velocity of the particle is 60 $\degree$ ?

What current in a solenoid 15.0-cm long wound with 100 turns would produce a magnetic field equal to that of the Earth,5.00 *10 ^{- 5} T?

A coaxial cable has an inner cylindrical conductor surrounded by cylindrical insulation and an outer cylindrical conducting shell.The outer shell carries the same current but in the opposite direction from that in the inner conductor as shown.If the coaxial cable sits in a uniform magnetic field directed upwards with respect to the cable,the effect of the field on the cable is

A stream of electrons passes through a velocity filter where the crossed magnetic and electric fields are 0.020 T and 5.00 * 10⁴ V/m,respectively.Find the kinetic energy (in electron volts)of the electrons passing through the filter.[1 eV = 1.60 *10 ^{- 19} J]

An ideal solenoid of radius a has n turns per unit length and current I.The magnetic flux $\phi$ _B through any area completely inside the solenoid,centered on the solenoid axis but at a 45 $\degree$ angle to the axis,so that it touches the inside of the solenoid,as shown below,is

Two long straight parallel wires separated by a distance of 20 cm carry currents of 30 A and 40 A in opposite directions.What is the magnitude of the resulting magnetic field at a point that is 15 cm from the wire carrying the 30-A current and 25 cm from the other wire?

The point P lies along the perpendicular bisector of the line connecting two long straight wires S and T perpendicular to the page.A set of directions A through H is shown next to the diagram.When the two equal currents in the wires are directed into the page,the direction of the magnetic field at P is closest to the direction of

Bert says that a charged particle in a vacuum can travel in a helix only if a uniform electric field and a uniform magnetic field are both present and both parallel to the axis of the helix.Stuart says that only a magnetic field with a component parallel to the axis of the helix is needed.Which one,if either,is correct,and why?

What is the magnitude of the magnetic force on a charged particle (Q = 5.0 $\mu$ C)moving with a speed of 80 km/s in the positive x direction at a point where B_x = 5.0 T,B_y = -4.0 T,and B_z = 3.0 T?

A circular coil (radius = 0.40 m)has 160 turns and is in a uniform magnetic field.When the orientation of the coil is varied through all possible positions,the maximum torque on the coil by magnetic forces is 0.16 N . m when the current in the coil is 4.0 mA.What is the magnitude of the magnetic field?

At a point in space where the magnetic field is measured,the magnetic field produced by a current element

A current-carrying 2.0-cm long segment of wire is inside a long solenoid (radius = 4.0 cm,n = 800 turns/m,current = 50 mA).The wire segment is oriented perpendicularly to the axis of the solenoid.If the current in the wire segment is 12 A,what is the magnitude of the magnetic force on this segment?

A solenoid 4.0 cm in radius and 4.0 m in length has 8 000 uniformly spaced turns and carries a current of 5.0 A.Consider a plane circular surface (radius = 2.0 cm)located at the center of the solenoid with its axis coincident with the axis of the solenoid.What is the magnetic flux through this surface? (1 Wb = 1 T . m²)

What is the magnitude of the magnetic field at point P if a = R and b = 2R?

A proton moves around a circular path (radius = 2.0 mm)in a uniform 0.25-T magnetic field.What total distance does this proton travel during a 1.0-s time interval? (m = 1.67 *10 ^{- 27} kg,q = 1.6 *10 ^{- 19} C)

A single circular (radius = R)loop of wire is located in the yz plane with its center at the origin.The loop has a clockwise current as seen from the point (+R,0,0).The direction of the magnetic field at the point

A long straight wire (diameter = 2.0 mm)carries a current of 40 A.What is the magnitude of the magnetic field 1.5 mm from the axis of the wire?

The reason the north pole of a bar magnet free to rotate points north is because